I recently build gentoo-3.10.7-gentoo-r1 and after reboot i got some network interfaces AND I don't know IF i NEED THEM EVEN;
Please tell me if any or all of them are useful . also I want to find out which kernel feature; that I enabled ; make each one of them, in order to disable them.
By the way i build in the kernel the ability of .config file

only lo and wlp5s0 are the devices that i had before. Also in 3.8 kernel my Ethernet (eth0) didn't have the driver (CONIG_ALX) So there should be an eth0 there but in new naming paradigm. ( i guess it is enp3s0).

If the system worked before, and you do not know why you have the new interfaces, you probably do not need them. You can remove support for dummy0, gre0, sit0, and gretap0. You might or might not need tun10.

I expect this is not just your kernel but also due to UDEV. You should check the news article "Upgrading udev to version >=200". In short, if you create the file /etc/udev/rules.d/80-net-name-slot.rules and reboot enp3s0 might be eth0 again.